32-bit installation error-message on 64bit MacOs Matlab


I teach a Matlab course in which we use Psychtoolbox.
While installing on their personal PCs, 3 of my students who use Mac’s were unable to install (the other Mac-users were fine).

“Psychtoolbox 3.0.12 and later do no longer work with 32-Bit versions of Matlab.
You need to upgrade to a supported 64-Bit version of Octave or Matlab. 32-Bit Octave is still
supported on GNU/Linux.”

All cases were on M1-chip mac’s running Ventura and Matlab v2023b (so 64-bit).

I cannot find any systematic difference between students who could and couldn’t install and we have not been able to replicate the problem.

I think it is literally impossible that they are somehow running a 32-bit version of Matlab r2023b on Ventrua… so I’m at a loss.

If anyone has any thoughts or suggestions, they would be very much appreciated.

All the very best,


p.s. Just to see, we tried installing a legacy 32-bit version of PTB but were not able to do so successfully (not that this would have been a real long-term solution)

Probably they installed R2023b for native Apple Silicon (ARM architecture), which right now is not supported by PTB. Getting Matlab for Intel Macs and running in Rosetta2 emulation might work ok’ish enough for a teaching course, as opposed to real data collection. From Mathworks website:

" Is there a Universal macOS Binary available for MATLAB?

No. MATLAB for Intel Macs and MATLAB for Apple silicon Macs are separate applications. To run MATLAB in Rosetta 2 on an Apple silicon Mac, download and install MATLAB for Intel Macs."

I installed both ARM and Intel R2023b and not such a performance improvement as I hoped… Stick to the Intel version for now, AFAIK Mario said recompiling will be a non-trivial task (I did it for 64bit ARM Raspberry Pi but the dependencies are probably easier to deal with on Debian…)